Underreamer.



EDWARD NORTH, OF LS ANGELES, CALIFORNIA.

f UNDnnnEAMEa.

To all lwhom t may concern. l y

Beit known that I, EDWARD NORTH, a citizen of the `United States, residing at 4Los Angeles, in the -county of Los Angeles andyState of California, have invented a lnew `and useful Improvement in Under-v reamers, of which the following is a speci- 'y fication.

This invention relates to tools adapted to' enlarge the hole beneath the casing inthe operation of drilling and the like. A

Objects of 'this invention are easev of manufacture, simplicity of construction,-

smoothness of operation, superiority of action in expanding and contracting, superior strength, greater ease of assemblage and security against accidental disassembling.

It is a feature ofthe invention that the cutters are provided with fiat-faced Shanks that are seated in a fiat-faced socket when the tool is expanded in operative position,`

and in which the upper portions of the shanks 4are held irmly by straight edges contacting with flat faces when the tool is collapsed. By this construction'the cutters are held firm and'true when the tool iscollapsed so as to cause less trouble as the tool runs down the casing.

An object is to gain simplicity and strength of construction ascompared with other under-reamers of a similar general design and in this connection to eliminate the small comparatively weak dove-tailing` in use in some former under-reamers. To this end I furnish this tool with anarrangement of feathers andste s 0f novel construction and thus provide earingsur` faces and parts; of such strength as to be practically unbreakable; at the same time making the tool stronger and much simpler in construction. l

VAn objectV is to provide a superior underreamer 1n which all movable or working parts are assembled 'and the requisitel pressure or tension is put upon the spring, be# fore said workingI parts are inserted in the body; slots forl retaining keys being provided and so slanted on. the lower sides that as the keys arel driven into place they apv Specification of Letters Patent. Application med :une 2o, 1917. sei-mm. 175,943.

oil wells, water wells the tool expanded.

Patenten Apr. a, 191s.

plya slight added pressure yto the spring,

thus insuring against lost motion in the cutters when the tool is in operation. I also propose to insure safety, in that a stop preferably in the form of'a pipe inside the cutter-retracting spring absolutely prevents the `cutters from being .pulled down far enough to come off of the retracting-head, l'and thus avoiding all danger that the cutters be lost in the well. -An object is to -make an improvement in that the cutters, when contracted, are much more rigid in the body of the tool andwill,

therefore, cause less trouble in going down the casing, the advantage being due -to the differencel in construction between a circular recessed body, as in certain earlier pat-` tents, in which, as the cutters are withl.and various novel parts and combinations of parts particularly described and claimed herein.

Further objects and advantages may appear from the accompanying drawing, the

subjoined detail description and the appended claims.

rIlleiinvention' may be carried out with various forms of construction and'I do not4 propose to limit the construction to the exact form shown. although it is understood that the construction and arrangement of the various parts and faces are very important toward attaining-in toto all .the objects in view. H

The accompanying drawings illustrate the invention in 'a form I at present deem most satisfactory.

Figure 1 is an elevation of one side of Fig. 2 is a fragmental side elevation of the lower part of the tool shown in Fig. 1 turned quarter way around vfrom Fig. 1.

Fig. 3 lisla fragmental sectional elevation of the tool in the casing of a well. Dotted lines indicate positions of parts when the tool is expanded below the casing.

' Fig. 4 is a fragmental view of the tool shown in Fig. 3 from the side visible in Fig.'2, lthe body of the tool being shown in axial mid-section.

Fig. 5 is a bottom plan View from line m5, Fig. 3. Y

Fig. 6 is an axial fragmental section of the tool body on line m6, Fig. 5.

Fig. 7 is a fragmental axlal section of the tool body on line fr", Fig. 5.

Fig. 8 is a perspective of the outer side of one of the cutters. y

Fig. 9 is a perspective of the inner side of one of the cutters.

Fig. 10 is a 'cross-section on line m10, Fig. 4, looking up.

Fig. 11 is a bottom plan of the stock from which all other parts are omitted.

Figs. 1, 2, 6 and 7 are on one scale and Figs. 3, 4, 5, 8, 9 and 10 are on a larger scale. Fig. l1 is on a scale intermediate the scales of the other views. 'l

The tool body, stock or barrel 1 is preferably cylindrical in the main, and has the usual tool pin 2 andwrench square 3.

rlhe stock 1 is provided with a central oylindrical bore 4 and with a downwardly flaring socket 5 openingdownward lat the lower end of the stock. aid socket'has parallel flat upwardly reduced side walls 6 provided with steps 7 and communicates with lateral openings 8 at the lower end of said steps. Said socket is also provided with upwardly converging flat faces 9 having recesses 10 communicating with said lateral openings 8. rlhe inner edges 11 of the steps on' one side converge upwardly and are in parallelism with the upwardly converging inner flat faces 9 of the socket. The inner edges of the steps on the' other side are likewise constructed and arranged.

Each cutter l2 comprises a blade 13 having a iiat inner face 14 and terminating in a shoulder 15. Said cutters also have shanks 16, each having an inner flate face 17 oblique to the face 14 of the cutter blade. rll`he outer face 18 of the shank is flat and in the form shown extends in practical parallelism with i the produced axis ofthe cutter blade. Op-

posite faces 19, 19, of each shank are practically parallel to each other and are provided with feathers 20 extending from the flat inner face 17 of the shank toward the flat outer face 18 of said shank; and the outer edges 21 of said. feathers are practically in parallelism with said outer base `18.

rllhe vfeathers 20 are wedge-shaped, the upper ends being reduced and the space between the outer edges 21 of the feathers and the outer face 18of the shank being of uniform width from end to end of the feathers and corres ondin the space so t Aat when the shanks are seated, the ribs wedge into the space between n the steps in conformity with the wedging in width to the width of weasel action of the Shanks into the space between the converging flat faces 9 of thei'socket. rlhis construction greatly increases the strength and rigidity of the tool at the moment the blow is struck and allows an immediate yielding or retraction of the cutters on the upstroke of the tool.

rlhe shanks are provided with retainer seats 22 in the form of perforations that are shown as circular at the outerside of the shank and which iare inwardly toward the oblique face 17 and terminatein grooves 23 to accommodate the suspending rod 24 which has a cutter support 25 in the form of a T head or projection at the lower end of the rod. The upper end of said rod is itted with a retainer in the form of a nut 26 threaded onto said rod to support the thrust against a washer 27 by the cutter supporting and retracting spring 28 which is mounted onfthe lower washer 29 that is supported by a pair of keys 30 driven into seats 30 provided therefor in the stock above the downwardly Haring socket 5.

Said seats are slots extending in parallelism with each other 'through the stock on opposite sides of the yaxis thereof and spaced apart tohold the keys 30 suliciently apart to accommodate the supporting `rod 24 between them; but arranged close enough together to support the washer 29 which in turn supports the spring 28. Said suspending rod is provided with a shoulder 31 adapted to pass between the keys 30 and to support the washer 29 duringthe operation of assembling.

The upper walls of the key-ways are normal to the axis of the stock 1, and the lower walls of said key-waysare aslant from one to the other side of the stock to accommodate the wedge-shaped keys 30, so that when the keys are inserted under the washer 29 and driven home into their seats there will be a slight wedging action to-tighten saidv washer against the spring to increase the tension thereof so as to draw the cutters more -irmly into the seat therefor.

A. stop 32 to limit the approach of the washer 27 and retainer or any equivalent thereof when the parts are assembled and the tool is in operation, is provided between the washers 27, 29 and within the helical spring 28. Said stop is shown as a piece of pipe around the suspending rod and inside the cutter supporting spring.

The stock 1 is pierced. with a' hole 33 at one side of the bore 4 and extending from side to side of the stock at one end of the key-slots 31, and the keys 30 are pierced to receive a pin 34 passed through the hole 33 when the keys are fullyl seated. Said pin is preferably a piece of wire of sufficient size to hold the keys in place. Said wire is bent at its ends inside the recesses 35 at the ends of the hole 33 to prevent'the accidental greater diameter than the the coil spring. p

To assemble the tool the lower Washer 29 will first be applied to the supporting rod 24 and brought to rest upon the shoulder 31. Then the stop 32 will be put onto the supopen space inside porting rod to rest against "the washer 29 and the helical spring 28 will be applied to the rod outside of the stop 32, then the washer 27 will be put in place on the sup-v porting rod and against the end of the spring 28, and then the nut 26 will be screwed home to compress the spring. The spring 28 when not compressed will normally be almost as long as the length of rod between the shoulder 3l and the threaded end of the suspending rod, so that when the nut is screwed home on the upper washer 27,

the springv will be slightly compressed thereby before the nut is fully seated. The

threaded portion 36 of the supporting rod When the supporting rod, the washers,.

stop, spring and nut have thus been assembled, the cutters will be Aadjusted to the ends of' the T head 25 and the supporting rod with its nut, washer and spring will vbe inserted into the bore of the tool to bring the washer 29 beyond the key-ways and at the same time bringing the shanks of the cutters together within the socket, the oblique Hat faces 17 of the shanks being in contact with each other as ,shown in Fig. 1 in solid lines and in Fig. 3 in dotted lines. Then the keys 30 will be inserted and driven home, the first action of said keys as they aredriven home being to wedge the lower washer 29 `upward to compress the spring and draw the cutter Shanks up into the socket therefor.

When the parts are thus secured together the keysjare finally fastened by the wire pin 34 and the ends of the pin are bent over in the side recesses 35. The tool is then ready to be connected to the usual parts, not shown, to complete a string of tools, and is thus ready to be inserted into the casing. For the purpose of inserting the tool into the casing, t e cutters will be dra-wn down into the posi ion'shown in solid lines in Fig. 3, and the cutters will then be inserted into the casing with which the usual runners 37 contact. .The tool may then be lowered and the runners Vwill rundown on the inside of the well casing until they escape from the lower end of the casing. vThereupon the spring 28 will retract ,the cutters andthe upper square edges 18 of the shanks will run 'cutters into the osition shown in dotted displacement thereof. .The washers are of enter the lower edge of the shoe of the casing l and run up inside the casing as is usual with cutters of this class of tools while being Withdrawn from a casing.

Among the features of novelty that have been disclosed particular attention vis directed to the following:

Portions of the cutters t into the recessed part of the body of the tool in which there are provided the steps or flanges of such great cross section as to practically obviate all chance of breakage. These flanges take the place of weaker d'ove-tailing in other tools of somewhat similar type.

The rectilinear form of the 4upper part or shank of the cutter increases very greatly the Vstrength at that point where it is necessary to bore it out to provide channels for the supporting rod and cross-head. v

It is believed that no other under-reamer the cutters of which rock upon each other;

that is to say, under-'reamers in which no intermediate or dividing wedge is used inexpanding the cutters to working position, has cutters, the Shanks of which have this form with its attendant advantages.

The construction of the body or barrel of the tool includes the specially-formed recess in which the shanks ofthe cutters operate. The upper end terminates in the customary tool-joint. A cylindrical cavity of the required depth and of such diameter as may be necessary to take vthe suspending rod with. its surrounding stop of pipe, or otherwise,

operating spring with bottom bearing,

washer or otherwise, and compression nut, or other meansof maintammg proper compression on the spring, is provided, extendthe lower side of the bottom bearing, or`

washer support of the spring, the taper being such-that as thekey is forced to its -ultiy mate position a slight additional tension is put upon said2 sprin so as teinsure the cutters being held r v,y in their operative poioc- "sition; these keys being kept from wor.

of these keys, or ot er similar means, such as screws.

The recesso'r cavity at the bottom of the barrel is provided not only with recesses to fit and engage the steps on the shanks of the cutters so as to hold them rigid when in operation, but is so shaped as to bear against the upper ends of said shanks and thereby reinforce the action of the steps and their corresponding recesses in preventing the closing together of said cutters when in operation.

The -supporting-rod (which is preferably made in one piece, and in 'l' form, though it may be made straight, with a slotted head through which a key may be placed) has, as shown, an enlarged section (3l) near the lower end, for the urpose of supporting the lower bearing ofP the spring. rIhis enlarged section is not essential, as any other means of holding the lower bearing of the spring against the pressure' put on by the compression nut at such times as the underreamer is not assembled and ready for operation will be satisfactory.

I claim l. An under-reamer having a flaring flatfaced stepped socket in its lower end and a bore extending upward from the socket; cutters having feathered Shanks to conform to -said socket when the cutters are expanded for under-reaming; said cutters being provided with orifices flaringv inwardly; and

a supporting rod having a head in said orifices and a spring to retract said head toward the top of the socket; the feathers of said Shanks being upwardly reduced and the outer feathered edges being in vparallelism with the outer face of the Ishank and the space between' the outeredges corresponding with the width of the steps of the socket.

2. An under-reamer having a flaring :fiatfaced socket in its lower end and a ,bore eX- when the cutters are expanded for underreaming, said cutters being providedwith naeaeei ,orifiices Haring inwardly, and a supportingv rod having a head in said orifices, andv aV spring to retract said head `toward the top of the socket; opposite side walls of` said socket being recessed to Ireceive the ends of the head when the same is fully retracted and the cutters expanded; said socket being provided with converging steps and said shank with upwardly reduced feathers for the purpose of assisting to resist the work- `ing blow and torelease the cutters immediately upon the beginning of the upstroke. 3. An under-reamer comprising a stock having a socket in its lower end; and cutters yieldingly held in said socket and provided with shanks having feathers on their sides at the inner edges thereof; said socket conforming to the Shanks and provided with steps to seat said feathers; the steps being of uniform width and the feathers upwardly reduced as and for the purpose set forth.

4. An under-reamer comprising a body provided with a central bore terminating in a socket at the end of the body and also provided with transverse key-ways, said socket having two parallel faces in continuation of said bore and two diverging faces between the outer edges of the parallel faces, said parallel faces being recessed, the recesses having rectilinear walls, said divergingy faces being recessed, said recesses in the diverging faces having at the upper ends seats for the ends of a cross head, under-reamlng cutters having Shanks to conform to the stem; nand wedging keys in. the key seats to l support the spring-supporting means.

In testimony whereof, I have hereunto set my hand at Los Angelesa California, this 15th day of June, 1917.

EDWARD NORTH.

Witness:

JAMES R. TowNsEND. 

